Conventional waterless cleaning compositions contain as much as 45% by weight organic solvents and as much as about 7 weight percent of emulsifiers in order to solubilize grease or soil. These compositions require high concentrations of organic solvents and emulsifiers to remove hydrophobic materials through dual actions of emulsification and solvation. These conventional cleaning compositions have fallen out of favor owing to the high percentage of solvents and emulsifiers that end up in wastewater, as well as the skin irritation associated with the use of such products. The high concentration of organic solvents and emulsifiers makes subsequent removal difficult, often resulting in a residual film that retains soil and/or grease while the film tends to dry and irritate the underlying dermis.
Previous attempts to form a cleaning composition that uses lower percentages of solvents and emulsifiers have met with limited success. Cleaning compositions with low hydrophilic lipophilic balance (HLB) emulsifiers tend to have excellent degreasing properties yet are difficult to remove with aqueous washing. Alternatively, oil and water emulsions formed with high HLB value emulsifiers tend to have lower percentages of organic solvents and are readily rinsed off of a surface with an aqueous wash yet provide poor grease removal. Cleansing compositions with intermediate HLB value emulsifiers tend to have acceptable cleansing and aqueous rinsing properties yet suffer phase separation upon storage. Previous attempts to stabilize intermediate HLB value emulsifiers have resorted to complex combinations of expensive and enviromentally disfavored surfactants. Alternatively, high loadings of thickeners and/or specifically tailored organic solvents have been used. A further complication in providing a cleaning composition based upon an intermediate HLB value emulsifier is that often emulsion stabilizers also function as co-emulsifiers thereby shifting the resulting cleaning composition from the desired intermediate HLB value range that provides effective degreasing and aqueous rinse properties.
In addition to cleaning compositions, skin moisturizing lotions have traditionally included 8-12 weight percent organic solvents and 3-4 weight percent emulsifiers. A lotion is intended to retain water in contact with skin yet avoid a greasy skin sensation. For a lotion, degreasing properties are less important than aqueous rinsing ability and therefore lotions tend to contain higher HLB value emulsifiers, as compared to cleaning compositions. A higher composition HLB value tends to provide a lighter, clean sensation on applied skin. Prior art attempts to reduce the amount of organic solvents and emulsifiers and lotions also have met with limited success.
In view of the state of the art, there exists a need for a cleaning composition containing reduced percentages of organic solvent and emulsifiers. There also exists a need for a lotion or cleaning composition containing an intermediate HLB value emulsifier having acceptable degreasing and aqueous rinsing properties, while maintaining a suitable shelf life.